Hydrodynamic dampers are used in gas turbine engines to damp vibrations at rotating bearings. A film of oil is provided between the rotating bearing and the bearing support in order to damp these vibrations. This oil is often supplied through a tube. It is desirable in some applications for the oil supply to the hydrodynamic damper to be scheduled, i.e., turned off during some engine operating conditions in order to change the stiffness of the bearing. The need to turn off the oil flowing through the oil supply tube prevents the use of such tubes in hot sections of the engine where temperatures are high enough to cause coking of the oil residue remaining in the oil supply tube when oil is not continuously flowing therethrough.
Improvements are therefore needed in gas turbine engine oil supply tubes.